Multicolor lighting apparatus



June 11, 1968 D. R. LARSEN MULTICOLOR LIGHTING APPARATUS 4 Sheets-Sheet1 Filed Jan. 21. 1966 Rm m MM m e v m 7 D A M M June 11, 1968 LARSEN3,388,245

MULTICOLOR LIGHTING APPARATUS Filed Jan. 21, 1966 4 Sheets-Sheet 4INVENTOR. Dom/440 2. 4 4255 United States Patent 3,388,245 MULTICGLGRLIGHTING APPARATUS Donald R. Larsen, Buena Park, Calih, assignor t0 theestate of Verneur E. Pratt Filed Jan. 21, 1966, Ser. No. 522,195 Claims.(Cl. 2403.1)

ABSTRACT OF THE DISCLOSURE In one embodiment a light is provided whichhas two or more filaments with associated different colored colorfilters. The filaments are connected in series between a first and asecond electrode through bimetallic strips. The second electrode extendsannularly around the first electrode with the strips biased against thesecond electrodes annular portion to effect a normally closed circuit.The filters are arranged to obtain a resultant color when two or morefilaments are energized simultaneously. In an alternate form theproduction of a resultant color is effected through a bimetallic stripactuated commutator. A third form of the invention includes a bimetallicspring which is coupled to the color filters. The spring is operable toexpose individual of the color filters to a single filament and toexpose adjoining filters to effect the resultant of their color.

This invention relates to a lighting apparatus having the capability ofproducing different colored lights at different times. Moreparticularly, this invention relates to a lighting apparatus which iscapable of producing certain individual colors as well as colors whichare a resultant of the individual colors.

Lighting apparatus capable of producing different colored lights areknown and employed, for example, in advertising, decoration andornamental displays. These apparatus either employ a plurality ofdifferent colored light sources or a single light source capable ofcasting different colored light at different points of time. However, nolighting apparatus characterized by a single source of light capable ofproducing different individual colors and the resultants of theseindividual colors has heretofore been devised.

The instant invention has the capability of producing, at differenttimes, each of a selected group of individual colors as well asresultant colors of the individual colors. Briefly, the inventioncontemplates the use of at least one source of light together with atleast two associated color filters. The source of light and colorfilters are housed in an envelope. Each of the color filters used hasthe ability, when exposed to the source of light, to produce one of theselected group of individual colors. These filters cooperate with one ormore sources of light in such manner that their individual colors aswell as a resultant color of at least two of the filters is capable ofbeing produced and observed by a viewer at different times. Toaccomplish the change in color, means are provided for exposing each ofthe filters individually to the source of light to produce its color,and for exposing at least two filters to the source of light at the sametime to produce a resultant color.

The selected group of individual colors, each of which is produced byexposing one of the filters to the source of light, is preferably of theclass of colors consisting of red, blue, green and yellow. The use ofthe primarycolors red, blue and yellow, theoretically produces thecapability for the widest variety of colors along the color spectrum.However, it has been found that for at least some arrangements, thesubstitution of green for yellow will produce a white light when thegreen, blue and red filters are simultaneously exposed to the source oflight. Nonethe- 3,388,245 Patented June 11, 1968 less, the choice ofcolors which form the selected group of individual colors is dependentupon the colors sought to be produced and, accordingly, this inventionis not limited to the use of the primary colors.

In one embodiment of this invention, a lighting apparatus capable ofproducing multiple colors is achieved by using a plurality of filamentsdisposed within an envelope as sources of light. These filaments arecapable of being in electrical communication with a source of electricalenergy and are energized to produce light by such energy. Associatedwith each of the filaments is a color filter capable of producing one ofthe selected group of individual colors when its associated filament isin electrical communication with the power source. Such an associationis preferably produced by enclosing each of the filaments in acylindrical color filter fabricated from, for example, light-perviousglass. The filaments and filters are disposed in an envelope. Each ofthe filters and its corresponding filament is positioned relative to atleast one other filter and its corresponding filament to produce aresultant color of the two individual filter colors when both filamentsare energized. Different of the individual colors of the selected groupof colors and at least some of their resultant colors are produced byhaving the facility to interrupt the electrical energy supplied to eachof the filaments at different points in time. This facility ispreferably accomplished by inserting a bimetallic member in electriccircuit with each of the filaments. The heat from the filament willincrease the temperature of the bimetallic member causing itsdeflection; the deflection opening the circuit. After the circuit isopen, the bimetallic member cools and deflects back into circuit withthe filament reestablishing current flow and light. The bimetallicmember can be warmed by other means including a heating coil connectedin such a mannor as to be periodically energized and deenergized, aswell as through its electrical resistance.

Another embodiment of the present invention envisions the use of a colorselector disposed away from the sources of light. The color selectorcontrols the production of each of the group of selected colors andvarious of their combinations through a commutator having individualsegments each electrically insulated from the other. As in thepreviously described embodiment, a plurality of filaments is used as thesources of light. Each of the filaments is in association with a colorfilter capable of producing one of the selected group of individualcolors. More than one envelope and filament unit may be convenientlyemployed by, for example, connecting a filament in one envelope inparallel with corresponding filaments in another envelope. Each of thecommutator segments is in electrical communication with one of thefilaments and has a conductive and a nonconductive portion. A wiper armis disposed relative to the commutator to sweep across each of thesegments. The wiper arm conducts electricity to each of the segmentsenergizing the filaments unless it is positioned over a nonconductiveportion. Connected to the wiper arm is a bimetallic member which isheated by a heating coil. The heat produces a deflection which -movesthe arm relative to the commutator. When the arm reaches a predeterminedpoint, current flow to the heating coil is terminated, and the member isallowed to cool. As the member cools, it forces the wiper arm to retraceits path over the commutator conducting current to the conductiveportions of each segment and in turn to the filaments. When thebimetallic member is sufficiently cool, the heater coil is againactivated and the heating cycle is begun anew. Thus the commutatordetermines the flow of current to each of the filaments in an envelopeor a plurality of corresponding filaments in a plurality of envelopes.At different points in time different individual and combinations of thefilaments can be energized causing different colored light to beproduced.

In still another embodiment of the present invention, a commutatorhaving a plurality of segments each electrically insulated from theother is once again used. Each segment is in electrical communicationwith a filament in an envelope having a plurality of filaments. Adifferent colored color filter is associated with each of the filaments.A bimetallic wiper arm in electrical communication with a power sourcedetermines which of the filaments is energized by sweeping back andforth across the commutator and conducting current to each of thesegments at different times. The portion of the wiper arm in contactwith the commutator is of sufficient dimension to contact more than onesegment as it traverses from one segment to the next adjoining segment,thus energizing two filaments in an envelope producing a resultantcolor. The bimetallic wiper arm is heated by a heating coil to cause itsdeflection in one direction. Current flow to the heating coil isperiodically terminated to allow the wiper arm to cool and deflect inthe opposite direction. This switching is preferably accomplished byusing a bistable member which is displaced from one position to anotherwhen the wiper arm reaches the limits of its travel in either direction.The bistable member turns a switch on at one extreme of its travel andthen off at the other extreme, energizing or de-energizing the heatingcoil.

In still another embodiment of this invention, multicolored light isproduced from a lamp having but a single filament. This is accomplishedby producing relative motion between the color filters and the filamentin such manner that the filters are individually and collectivelyexposed at different points of time to produce different colors. Thefilters can be conveniently moved through the use of a bimetallicmember, which, as it cools and expands, moves the filters in relation tothe filaments. Other means for moving the filters in relation to thefilament are also possible, such as through the use of a small vibratorymotor which drives a ratchet wheel which in turn drives a drive chain tomove the filters.

In all the above described embodiments as well as others which willoccur to those skilled in the art, it has been found that frosting theinterior or exterior of the lightpervious enclosure enhances theresolution of resultant colors to produce a more uniform colorobservable by a viewer. Moreover, while all the preferred forms of theinstant invention employ electrically operated filaments as sources oflight, other sources could be used, for example, small neon bulbs.

One of the distinctive features of the present invention is the abilityto produce more colors than the number of color filters used in anenvelope. This facility makes the production of many colored lightsfeasible at low cost thus overcoming the necessity of employingdifferent lamps of different colors. Moreover, the effect produced ismore startling because the many colors are produced from but oneenvelope. Within the ambit of the instant invention are severalembodiments allowing a broad range of colored lighting selection fordifferent applications. For example, the choice between external andinternal switching of colors is possible and the choice betweenillumination akin to a household incandescent lamp on the one hand andflood lighting on the other is possible.

These and other features, advantages, and aspects of this invention willbe developed and become more apparent from the following description,appended claims and drawings, in which:

FIGURE 1 is an elevational view, partly in section, of one embodiment ofthe instant invention;

FIGURE 1a is a perspective view of the filament and color filterassembly of FIGURE 1;

FIGURE 2 is a plan view, partly schematic, of another embodiment of thepresent invention;

FIGURE 2:: is a schematic view of the electric circuit of FIGURE 2;

FIGURE 3 is a perspective view, partly schematic, of still anotherembodiment of the present invention;

FIGURE 4 is a side view partly in section of still another embodiment ofthe present invention; and

FIGURE 4a is a schematic of the electric circuit of FIGURE 4.

Referring now to FIGURES 1 and 1a there is seen a typical lightingapparatus 15 having a light-pervious envelope 14 secured to cap or base3. Within the envelope 14 is a standard insulator 2 which serves tosupport and insulate center electrode 10. The upper portions ofbimetallic members 1, here shown as bimetallic strips, are secured inthe upper portion of the insulator 2, as shown. A portion of electrode 7is annularly disposed about and spaced from the insulator 2; theelectrode 7 also being in electrical communication with the cap 3. Thebimetallic strips 1 are biased against and normally in electricalcommunication with the annular portion of electrode 7. Each of thefilaments 8 is serially connected to one each of the bimetallic strips 1and each extends through insulating spacer 11 to be secured inelectrical communication with the center electrode 10. Thus, each of thefilaments and its corresponding bimetallic strip is in parallel witheach other filament and bimetallic strip combination. The bimetallicstrips are disposed to deflect inwardly, upon heating, towards theinsulator 2 away from the annular portion of the electrode 7. Heating ofthe bimetallic strips is produced by virtue of electric current flowingthrough the strips; however, it has been found that the filaments areprimarily responsible for the heating of these strips. When sufiicientlyheated, each of the bimetallic strips will break the electrical circuit.to their respective filament. Around each of the filaments is disposed adifferent colored color filter. These filters are preferably cylindricalin order that they completely surround the filaments to produce auniform color. The color filters and filaments are preferably disposedin a cluster with each color filter-filament combination being roughlyparallel to the other color filter filament combination. This array ispreferred because it allows the assembly of filters and filaments to berelatively compact, thus producing a unit source of light. The color ofeach color filter is preferably selected from the colors: red, blue,yellow or green; but, for purposes of description the primary colorswill be used. The red, yellow and blue filters are denoted by referencenumerals 9, 12 and 16 respectively. Insulated ring 5 insulates basecontact 4 from the base or cap 3. When the inner surface 13 or outersurface 17 of envelope 14 is frosted, a truer resultant colored light isobserved by a viewer because of the diffusion caused by the frosting.

The operation of the embodiment shown in FIGURES 1 and la is dependenton the flow of electric current from electrode 7 through the bimetallicstrips 1 and filaments 8 to electrode 10 and the periodic interruptionof current through each filament bimetallic strip combination. When incircuit, each filament emits a different colored light through itsrespective color filters. Because these color filters are of differentcolors, there will be resultant colored light seen by an observer whenmore than one filament is energized. The periodic interruption ofcurrent through each filament-bimetallic strip combination isaccomplished by the warming of the bimetallic strips and their resultingdeflection inwardly away from and out of contact with electrode 7. Oncean individual bimetallic strip is out of circuit, it will cool anddeflect back into contact with electrode 7, thus reestablishing thecircuit to its corresponding filament. The tendency of the bimetallicstrips to move inwardly under the influence of heat may be adjusted bybiasing them against the annular portion of the electrode 7.

Circuit interruption can be made to occur in a random fashion throughdifferences in biasing pressure and the geometry between the bimetallicstrips. Differences in the color observed by a viewer are typicallyproduced as follows: When the bimetallic strip leading to the filamenthaving a blue filter 16 is out of circuit, and the remaining bimetallicstrips and their corresponding filaments are in circuit, the resultantcolor viewed by an observer will be orange. Similarly, when the circuithaving red filter 9 is out of circuit and the circuits to yellow andblue filters 12 and 16 respectively are energized the resultant colorviewed will be green. When the yellow filter 12 is not exposed and thered and blue filters 9 and 16 respectively are exposed to the lightproduced by their filaments, the resultant color will be violet. It isobvious that with different combinations of filaments in circuit,diflerent colors will be observed. Moreover, it is clear that one of theprimary colors, red, blue or yellow, will also appear to an observer inthe course of events. In addition, it is also possible to use colorfilters capable of producing colors other than the primary colors.

FIGURES 2 and 2a depict still another embodiment of the instantinvention wherein the diflerent colors observed by a viewer arecontrolled by a selector 60 outside of a lighting source or sourcesenclosed in light-pervious envelopes 5t) and 51. Mounted on base 21 ofthe selector 60 is a commutator 59 having conducting strips or seg mentsshown by reference numerals 40, 41 and 42, respectively, whichcorrespond, for example, to the primary colors blue yellow and redrespectively. Each of these strips is electrically insulated from theother and has a nonconductive portion 61. Electrically connected tosegments 4t), 41 and 42 are leads 24, 23 and 22, respectively. Currentto each of the segments 40, 41 and 42 is supplied from the upper section25 of wiper arm 36 through its brushes 43. Current to the upper section25 of the wiper arm 36 is in turn supplied through one of the brushes 43which is in electrical communication with conductive segment 39 which inturn receives electrical energy from a power source through leads 58 and35. The wiper arm 36 moves back and forth across the commutator 59 toaccomplish selective illumination of the filaments 57 disposed inenvelopes 50 and 51. This movement is produced through the use ofbimetallic strip 33 and the toggle spring 28. The bimetallic strip 33 issecured at one end to the lower section 26 of the wiper arm 36, and isanchored on base 21 at its other end by anchoring means 34-. Thebimetallic strip 33 is preferably heated by bimetallic strip heatingcoil 32 which receives its electrical energy through lead 35 from thepower source. The circuit including heating coil 32 is completed byvirtue of the conductivity of the lower section 26 of the wiper arm 36which is in electrical communication with toggle plate 31 which in turnis normally in contact with lead 56 through conductive stop 29. Theupper section 25 and the lower section 26 of the wiper arm 36 are, ofcourse, electrically insulated from each other. As the bimetallic strip33 is heated it urges the wiper arm 36 across the commutator 59 untilthe toggle spring 28 moves to the left of the wiper arm 36 and togglepin 37 whereupon the toggle plate 31 rotates about the pin 37 againststop 38. In this position, the heating coil 32 is no longer in circuitand the bimetallic strip 33 begins to cool and move the wiper arm 36back across the commutator 59. This movement continues until the circuitto the heating coil 32 is reestablished when the toggle plate 31 movesagainst contact 29, from the action of the toggle spring 28, as itpasses to the right of the toggle pin 37. The toggle spring 28 ismounted on the lower section 26 of the wiper arm 36 by pin 27 and on thetoggle plate 31 by pin 30. The selector 60', as previously mentioned,determines the flow of current to the lighting sources in the form offilaments 57 in envelopes 56' and 51. The filament envelope arrangementhere is much the same as described with reference to FIGURES 1 and 1m,with the exception of the absence'of bimetallic strips or switchingmeans within the confines of the envelopes. Accordingly, many of theconsiderations previously described are applicable here. Thus, each hasthree filaments 57 around each of which is disposed a different coloredcolor filter. Leads 22, 44 and 45 are to the filaments having anassociated red color filter. This circuit is completed by providingcommon 52 from within envelope 50 and common 53 from within envelope 51,both of which are connected to leads 54 and 55. Similarly, electricalcommunication to the filaments corresponding to the yellow filters isprovided by leads 23, 46 and 47, and to the filaments corresponding tothe blue filters through leads 24, 48 and 49. The completion of thesecircuits is effected through commons 52 and 53, together with leads 54and 55. Thus, each of the circuits corresponding to each of thedifferent colored filters is in parallel with each of the other circuitshaving dilterent colored filtersqMoreover, each of the filamentscorresponding to one of the colored filters is in parallel with allother filaments corresponding to the same colored color filter.

In operation the selector lighting source combination shown in FIGURES 2and 2a allows individual illumination of each distinct colored filterand simultaneously illumination of different colored filters to producea resultant color. As the wiper arm 36 moves across the commutator 59 bythe action of the bimetallic str p 33, the brushes 43 will contact theconductive and nonconductlve portions of the segments 40, 41 and 42.When a brush is in contact with a conductive portion of a segment,current will flow in its corresponding circuit. Thus, in the positionshown, current is capable of flowing to all three segments 40, 41 and 42and leads 24, 23 and 22, respectively, to all three filaments in each ofthe envelopes 50, and '51 producing a resultant light of the threecolors: red, blue and yellow. When the wiper arm 36 is in the positionshown in phantom, that is, on the left side of the commutator, only thered conductive segment 42 is in electric circuit. Current will then flowthrough lead 22 to its filaments producing red light by virtue of thered color filter. For various positions of the wiper arm differentcolors will be observed by a viewer of the lighting sources asspecifically indicated in FIGURE 2. In the the embodiment shown thewiper arm 36 always conducts current whether it is sweeping to the leftor tothe right. Accordingly, at least some of the filaments will be inelectric circuit producing light.

FIGURE 3 shows still another switching mechanism for energizingfilaments to produce various color combinations to a viewer. Thisswitching mechanism includes bistable member '71 mounted on base 70.Groove 77 within bistable member 71 receives an insulating collar 72 anda portion of bimetallic strip 75. On one end of the bistable member 71is a tip 76 which closes switch 94 to establish current flow through theswitch. The bistable member 71 is normally biased against the switch 94in one of its stable positions to keep the switch closed and the heatingcoil 96 in circuit. Bimetallic strip 75 is received in groove 77 but isnormally out of contact with the periphery of the insulating collar 72.Current flows into the metallic strip 75 through lead 97. Lead 97, aswell, completes the circuit to the heating coil 96. When the switch 94is closed current flows through the heating coil 96, and lead and .97,causing the heating of the bimetallic strip 75. This heating deflectsthe strip away from tip 76 and deflection continues until bimetallicstrip 75 contacts the insulating collar 72 which forces the bistablemember 71 away from switch 94 into its other stable position, causingthe latter to open. Upon the termination of current flow in the heatingcoil 96, the bimetallic strip 75 cools and moves towards the tip 76until it contacts the portion of the insulating collar 72, closest tothe tip 76. This latter contact forces the bistable member 71 throughits tip 76 to close the switch 94, lreestablishing current flow to theheating coil 96. The bistable characteristic of bistable member 71allows it to remain in the position forced onto it by the bimetallicstrip 75 until the latter forces it into a second position. Currentflowing through bimetallic strip 75 and wiper 74 passes into commutator73, having for purposes of illustration, red, yellow and blue segmentseach insulated from the other. The position of wiper 74 relative to thecommutator 73 determines which of the leads 78, 79 and 80 are energized.Because the wiper 74 can contact more than one of the segments of thecommutator, more than one of the leads, 78, 79 and 80 may be energized.When the wiper is in the position shown, current will flow into the redand yellow segments of the commutator 73, establishing the flow ofcurrent in leads 78, 79, 85, 86, 81 and 82, illuminating two of tlethree filaments 95 in light-pervious envelopes 92 and 93. Because of theyellow and red filters associated with the illuminated filaments anorange light will be seen by a viewer. Similarly, when the wiper 74passes over the blue segment, out of contact with the red and yellowsegment, current will flow through leads 80, 83 and 84 to the filamentshaving a blue color filter producing a blue light. The circuit to eachfilament is completed by common 87 for envelope 92 and common 88 forenvelope 93; both of these commons being connected to leads 89 and 91,the latter lead is connected to the voltage source.

With reference now to FIGURES 4 and 4a there is seen a single filamentembodiment of the present invention. Within flood lamp 110 is mounted afirst electrode 111 and a second electrode 112, which are seriallyconnected by a filament 113 and receive electrical energy through leads131 and 129. Leads 129 and 131 are insulated from each other andconnected to mutually insulated portions of cap 132. Cap 132 is of thetype found in most commercially available incandescent light sources. Onmounting board 122 which is disposed within flood lamp 110, is securedswitch 127 which is turned on and off by the movement of rod 124 as ittravels back and forth within the flood lamp 110. Rod 124 is journalledin sleeve 123. Bimetallic spring 120 is connected at one end to themounting board 122 and at its other end to end plate 118. The bimetallicspring is fabricated from a plurality of bimetallic strips so connectedto expand as a unit upon heating and to contract as a unit upon cooling.End plate 118 as well as end plate 119 are slidably mounted onelectrodes 111 and 112 and form a part of filter cylinder 114. Thiscylinder has a plurality of colored filters disposed along its surface.These filters may be, for example, red filter 115, blue filter 116, andyellow filter 117. Heating coil 121 is connected to lead 130, which inturn is connected to lead 131. The circuit to the heating coil 121 iscompleted through switch 127 by leads 133 into the switch 127 and byleads 128 and 129 from the switch 127. In some applications, a mask maybe introduced in association with filament 113 to channel its light onlythrough the color filters which are proximate thereto.

When the switch is closed, current will flow through lead 130 to heatingcoil 121, back through lead 133, the switch 127, and lead 128. Theheating coil 121, thus energized, causes the bimetallic spring 120 tomove away from the cap 132 which in turn causes the filter cylinder 114to move away from the cap 132. As the filter cylinder 114 moves awayfrom the cap 132 each of the filters 115, 116 and 117 will be in aposition relative to the filament 113 to create a distinct coloredlight. When yellow filter 117 is exposed to the filament 113 the l ghtproduced by the flood lamp will be yellow. As the filter cylinder 114continues to move away from the cap 132, blue filter 116 will be exposedto filament 113 and a blue light will be cast; however, before bluefilter 116 is fully exposed to filament 113, yellow filter 117 willstill be under its influence. The combined color of yellow and blue, orgreen will then be produced. Finally, as the filter cylinder 114 movesfurther away from cap 132, red filter 115 will come under the influenceof the filamcnt 113, first causing the combined colors of red and blue,violet, to be produced, and then red. When the filter cylinder reachesits furlhermost position away from the cap 132, shoulder will open thcswitch 127, terminating the flow of current in the heating coil 121. Thebimetallic spring 126 then begins to cool contracting and forcing thefilter cylinder 114 towards the cap 132. At a predetermined point,shoulder 126 on rod 124 closes the switch 127 to once again establishcurrent flow in heating coil 121, and the cycle is reinitiated.

With the teachings of this invention, those skilled in the art willappreciate that other means are available to produce distinct colors ofa selected group of colors as well as resultant colors produced bycombining two or more of the colors of the selected group of colors atdifferent times. For example, a bimetallic strip actuated ratchet wheelconnected to a drum type commutator may be used. Further, by way ofexample, it is possible to coaxially mount a plurality of color filtersin association with an appropriate drive in such manner as to exposeeach filter individually as well as two or more filters collectively inorder to achieve a multicolored lighting apparatus. In the embodimentdescribed with reference to FIGURES 4 and 4a, a coil type bimetallicspring can be used. Moreover, different color filter-filamentcombinations in different envelopes may be connected in the sameelectric circuit to produce different colors at the same time indifferent envelopes. Therefore, the following appended claims should notbe limited in their spirit and scope to the specific embodiments of theinvention just described.

What is claimed is:

1. A lighting apparatus capable of producing different colored light atdifferent times comprising:

(a) a light pervious envelope;

(b) at least two filaments disposed within the envelope;

(c) a color filter in the envelope associated with each of thefilaments, each of the color filters producing a distinct color upon theindividual energization of its associated filament, the color filtersbeing of different colors and disposed with respect to each other toproduce the resultant of the different colors when their associatedfilaments are simultaneously energized; and

((1) means for independently energizing each of the filaments to produceits associated color and for simultaneously energizing at least two ofthe filaments to produce the resultant of their associated colorsincluding:

(i) a base;

(ii) a commutator on the base having at least two segments, each segmentbeing electrically insulated from each other segment;

(iii) electrical conductor means for providing electrical communicationbetween each of the segments and a corresponding one of the filaments;

(iv) a bimetallic strip mounted on the base operable upon heating andcooling to electrically communicate each of the segments with a powersource at different times and to communicate at least two of thesegments to the power source at the same time; and

(v) means for periodically heating and cooling the bimetallic strip.

2. The lighting apparatus claimed in claim 1 wherein:

(a) at least some of said segments have a nonconductive portion and allhave a conductive portion;

(b) a wiper arm is provided which is pivotally mounted at a pivot pointon said base, the wiper arm having a first current conductive sectiondisposed for electrical communication with the conductive portions ofsaid segments and movement over said segments, the first section of thewiper arm being capable of providing electrical communication with thepower source; and

(c) the bimetallic strip is connected at one end to said wiper arm andat the other end to said base such that the means for periodicallyheating and cooling said bimetallic strip causes the first wiper armsection to move back and forth over said segments.

3. The lighting apparatus claimed in claim 2 wherein:

(a) said wiper arm has a second current conductive section electricallyinsulated from said first section, said wiper arm being pivotallymounted on said base in the second section, and said bimetallic stripbeing connected to the second section; and

(b) said means for periodically heating and cooling said bimetallicstrip comprises:

(i) a heating coil in heat communication with said bimetallic strip andin electrical communication with the second section of said wiper arm;

(ii) a toggle plate pivotally mounted at the pivot point and inelectrical communication with the second section of said wiper arm;

(iii) a toggle spring having one end connected to said wiper arm and itssecond end connected to said toggle plate; and

(iv) a first and second stop on said base spaced apart such that saidtoggle plate is capable of contacting only one of said stops at a time,said first stop being capable of electrical communication with saidtoggle plate and a power source to establish a circuit through saidheating coil, the second section of said wiper arm and said toggle platesuch that said bimetallic strip is heated by said heating coil anddeflected to force the first section of said wiper arm across thesegments to a position allowing said toggle spring to pivot said toggleplate about the pivot point away from said first stop and against saidsecond stop to break the circuit to said heating coil whereby thebimetallic member cools forcing the first section of said Wiper arm backacross the segments until said toggle spring pivots said toggle plateabout the pivot point to contact said first stop and to reestablish thecircuit to the heating coil.

4. The lighting apparatus claimed in claim 3 wherein said envelope isfrosted such that light passing therethrough from its interior will bediifused.

5. The lighting apparatus claimed in claim 1 including:

(a) a bistable member having one end attached to said base and its otherend capable of moving between a first stable position and a secondstable position;

(b) an electric switch activated to its on position when said bistablemember is in its second stable position and activated to its oilposition when said bistable member is in its first stable position; andwherein:

(i) said means for heating and cooling the bimetallic strip includes aheating coil in electric circuit with said electric switch, saidbimetallic strip being in heat communication with said heating coil; and

(ii) the bimetallic strip is attached at one of its ends to said baseand has a wiper at its other end, the wiper being capable of electricalcommunication with one of the segments at one time and at least two ofthe segments at another time and of movement back and forth across thesegments in response to the heating and cooling of the bimetallic strip,said bimetallic strip being in position to contact said bistable memberafter being heated by said heating coil to cause said bistable member tomove to its first stable position and in position to contact saidbistable member after cooling to cause said bistable member to move toits second stable position.

6. The lighting apparatus claimed in claim 5 wherein said bistablemember has a groove which receives said bimetallic strip, the groovehaving a dimension in the direction of the deflection of said bimetallicstrip slightly smaller than the total deflection of such strip when itis heated by said heating coil.

7. The lighting apparatus claimed in claim 6 wherein said envelope isfrosted such that light passing therethrough from its interior will bediffused.

8. A lighting apparatus capable of producing different colored light atdifferent times comprising:

(a) a light pervious envelope;

(b) at least one source of electrically actuated light disposed withinthe envelope;

(0) at least two different colored filters in the envelope capable oflight communication with the light source, each of the color filtersproducing its color upon its individual exposure to the source of light,at least two of the color filters being disposed with respect to eachother to produce the resultant color of the two filters upon theirexposure to the source of light;

(d) a mounting board within the envelope;

(e) a bimetallic spring secured at one end to the mounting board and atits other end to the color filters; and

(f) means for periodically heating and cooling the bimetallic springsuch that each of the color filters is independently exposed to thesource of light during successive time intervals and at least two of thecolor filters are exposed simultaneously to the source of light toproduce their resultant color.

9. The lighting apparatus claimed in claim 3 wherein said source oflight comprises a filament; said periodic heating means comprises;

(a) a heating coil in heat communication with said bimetallic spring;and

(b) a switch in circuit with said heating coil and turned on and off bysaid bimetallic spring as it reaches the extremes of its travel.

10. The lighting apparatus claimed in claim 9 wherein said bimetallicspring comprises a series of bimetallic strips with an end of the firstand last strip being respectively connected to the mounting board andthe color filters and with the remaining ends of the strips beingconnected in end-to-end fashion to form an acute included angle betweeneach connected strip, the strips being disposed :to expand as a unitupon heating by said heating coil and to contract as a unit when saidswitch is off.

11. The lighting apparatus claimed in claim 10 wherein said colorfilters are disposed on a color filter cylinder connected to the laststrip.

12. The lighting apparatus claimed in claim 11 wherein said envelope isfrosted such that light passing therethrough from its interior will bediffused.

13. In an incandescent type light of the type having an electricallyconductive base, a light pervious envelope on the base, and a basecontact electrically insulated from the base, an improvement comprising:

(a) a first electrode and a second electrode, the first electrode havinga portion extending into the envelope, the second electrode having aportion extending into the envelope annularly about and space away fromthe first electrode, one of the electrodes being in electricalcommunication with the base contact and the other of the electrodesbeing in electrical communication with the base;

(b) at least two filaments in the envelope, each filament beingconnected in series with the first electrode;

(c) a color filter disposed in the envelope for each of the filamentssuch that the color corresponding to each color filter is produced uponthe individual energization of such color filters associated filaments,at least two of the color filters being of difierent colors and disposedwith respect to each other to produce the resultant color of the twodifferent colors when their associated filaments are simultaneouslyenergized; and

(d) a bimetallic strip connected in series with each of the filamentsand disposed to urge against the annular portion of the second electrodeto maintain a normally closed circuit between the electrodes, thebimetallic strips being disposed such that upon the passage of currenttherethrough the strips tend to deflect away from the annular portion ofthe second electrode to open the circuit to their associated filaments.

14. The improvement claimed in claim 13 wherein:

(a) an insulator is included which extends from the base into theenvelope;

(b) the first electrode passes through the insulator into the envelopewith a portion thereof extending above the insulator;

(c) the filaments are connected to the portion of the first electrodewhich extends above the insulator; (d) the second electrode is annularlydisposed about the insulator; and

(e) each bimetallic strip is anchored at one of its ends in theinsulator with its other end being free, the free end of the bimetallicstrips extending below 12 the annular portion of the second electrode,the filaments being connected to the bimetallic strips proximate thelatters anchored ends. 15. The improvement claimed in claim 14 whereineach 5 of the color filters substantially encloses its associated filamnt.

References Cited UNITED STATES PATENTS 1,070,699 8/1913 Kitsee 240-31 X1,283,751 11/1918 Hay 240l0 1,649,975 11/1927 Parks 24041.25 X 2,133,60810/1938 Engelken 240-3.1 3,143,300 8/1964 Way 240-3.1

15 NORTON ANSHER, Primary Examiner.

M. H. HAYES, Assistant Examiner.

